1. Field of the Invention
The present invention relates to a safety position switch of the type comprising a push rod which responds to the movement of an actuator connected to a device to be made safe, in such a way as to become displaced along a main axis in order to assume a rest position and a working position, comprising an electrical device, in particular a contacts block, switchable according to the position of the push rod, by means of a lockable transmission mechanism actuated by the push rod, and comprising a device for locking the transmission mechanism, which has a head for locking the mechanism, the locking head being capable of assuming a locked position and an unlocked position.
2. Description of the Related Art
In order to simplify the description, the expression “safety position switch” will hereafter be replaced by the expression “safety switch”.
Safety switches of the type described above are known for example from the document EP 817 227. These switches are associated with devices to be made safe, such as dangerous machines.
The locking device of the transmission mechanism is frequently produced in the form of an electromagnet disposed laterally with respect to the actuating head/push rod/contacts block assembly. It can also be a manually controlled device, for example by a key, or a pneumatic device or any other similar driving device.
Other safety switches have an elongated arrangement, or are of the “vertical” type, such that the locking electromagnet is located in the axis of the push rod and of the contacts block to be actuated (see for example EP 801 801). This configuration is advantageous for responding to certain size prescriptions of switches. However, the switches of this type do not sufficiently disassociate the movement of the locking device with respect to that of the push rod.